This week, Thanksgiving and the first day of the Jewish holiday of Hanukkah will coincide for the first time since 1888, when Grover Cleveland was in his first term as president.

It’s given rise to a new name for the occasion: Thanksgivukkah.

“The bottom line is, it all comes down to the calendars,” Rabbi Yosef Wolvovsky, director of the Chabad Jewish Center of Eastern Connecticut, said.

The blending of Thanksgiving, which has been observed in the United States on the fourth Thursday in November since 1942, and the eight-day Festival of Lights is very rare. The fourth day of Hanukkah was on Thanksgiving in 1899, but back then, it was observed on the last Thursday in November.

The lunar nature of the Hebrew calendar makes Hanukkah appear to drift slightly from year to year, Wolvovsky said.

Because the Jewish day does not begin at midnight, but on the sunset before it, those celebrating both holidays will light the second candle of Hanukkah the evening of Thanksgiving Day, the first candle having been lit on Wednesday.

And the next time after 2013 that Thanksgiving falls on the first day of Hanukkah, when the second candle is lit, will be in the year 79,043. Stephen P. Morse, the architect of the Intel processor, even developed a special computer program to calculate the year.

It’s not as rare that the holidays partially overlap. The first night of Hanukkah began on Thanksgiving evening in 1918, and will do so again in 2070.

Many are taking advantage of the calendar coincidence.

Boston Mayor Thomas Menino is set to proclaim Thursday Thanksgivukkah, and in New York City, Macy’s will include a giant dreidel in its Thanksgiving Day Parade to honor the occasion.

Look around online, and you can even find T-shirts commemorating “Thanksgivukkah 5774.” It is the year 5774 of the Hebrew calendar.

As it does every year, the Chabad center plans to mark the start of Hanukkah by lighting a 9-foot Menorah candelabra Wednesday evening on the Colchester town green.

Plans also were under way last week to conduct a Hanukkah Hop on Thanksgiving Day, Wolvovsky said.

“People will go door-to-door, and there will be the ringing of bells,” he said.

Aside from the “wow” factor of computing the dates of the holidays, the coming of what others call Thanksgivukkah is a time for special reflection, Wolvovsky said.

“It’s a time to educate people and a great opportunity to show that both holidays indeed do have similarities,” he said. “To describe Hanukkah, the Talmud uses the words ‘days of praise and thanksgiving.’ ”